From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 13 May 2001 16:55:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 13 May 2001 16:54:58 -0400 Received: from 20dyn175.com21.casema.net ([213.17.90.175]:38926 "HELO home.ds9a.nl") by vger.kernel.org with SMTP id ; Sun, 13 May 2001 16:54:49 -0400 Date: Sun, 13 May 2001 22:54:15 +0200 From: bert hubert To: linux-kernel@vger.kernel.org Subject: Re: Linux TCP impotency Message-ID: <20010513225415.A4950@home.ds9a.nl> Mail-Followup-To: linux-kernel@vger.kernel.org In-Reply-To: <20010513213853.A5700@ghost.btnet.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0pre4i In-Reply-To: <20010513213853.A5700@ghost.btnet.cz>; from clock@ghost.btnet.cz on Sun, May 13, 2001 at 09:38:53PM +0200 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, May 13, 2001 at 09:38:53PM +0200, clock@ghost.btnet.cz wrote: > Using 2.2.19 I discovered that running two simultaneous scp's (uses up whole > capacity in TCP traffic) on a 115200bps full duplex serial port nullmodem cable > causes the earlier started one to survive and the later to starve. Running bcp > instead of the second (which uses UDP) at 11000 bytes per second caused the > utilization in both directions to go up nearly to 100%. > > Is this a normal TCP stack behaviour? Might very well be. Read about different forms of (class based) queuing which try (and succeed) to improve IP in this respect. TCP is not fair and IP has no intrinsic features to help you. http://ds9a.nl/2.4Routing contains some explanations and links. SFQ sounds like it might fit your bill. Regards, bert -- http://www.PowerDNS.com Versatile DNS Services Trilab The Technology People 'SYN! .. SYN|ACK! .. ACK!' - the mating call of the internet